Pressure casting apparatus



Z L U H C S J R PRESSURE CASTING APPARATUS 2 Sheets-Sheet 1 Filed April 1, 1936 3nventor 28, 1937. R. J. SCHULTZ V PRESSURE CASTING APPARATUS 2 Sheets- Sheet 2 Filed April 1, l.936

8 M m 5.m3% 4. ow 4 i|. T wwk Zinnentor attorneys Patented Dec. 28, 1937 UNITED STATES PATENT OFFICE 2,103,438 PRESSURE oAsTiNG APPARATUS Application April 1, 1936, Serial No. 72,161

10 Claims.

The present invention relates to pressure casting apparatus and, particularly, to that type of apparatus wherein plunger means function to transfer metal in a moldable state from a container to a mold and compress ittherein.

It is an important object of the invention to provide means whereby transference of the entire charge of metal from the container or well to the mold may be effected before the metal is placed under pressure, such, for instance, as would result from passage of the metal into the casting cavity or through the ingate. Thus, there is avoided the danger of metal under high pressure escaping from between the die and the well or container during the transferring operation. Furthermore, the absence of pressure on the metal with the arrangement referred to obviates the necessity of providing a tight fit between the metal well and the mold. This is particularly advantageous with bottom-gated, multi-part molds, as will. appear later.

Another important feature of the invention is the provision of means, adapted for ready adjustment, whereby the desired transference of the metal charge to the mold before the metal is placed under pressure may be accomplished irre-' spective of the size of the casting cavity of the mold used. i

A further object is the provision of means for readily adjusting the position of the metal receiving well so as to permit the use of different sized molds. Means are also included to insure proper alinement of the mold and the well during the metal transferring operation.

Simplicity and sturdiness of design, and efiicicncy of operation, whereby the machine is especially adapted for high pressure casting of high temperature metals, are further features of the invention. Other objects and advantages will appear hereinafter.

Reference is had to the accompanying drawings which illustrate a practical embodiment of the invention applied to a semi-automatic type of die casting machine.

Figure 1 is a front elevation of the die casting machine with certain parts in section to Fig. 3 is an enlarged fragmentary section sim-' ilar to a portion of Fig. 1, but showing the plunger raised and the metal charge moved into the die.

Fig. 4 is a perspective of one of the well adjusting members; and

Fig. 5 is a vertical section of the metal plunger and power piston coupling.

In the drawings, the die casting machine is shown as comprising a framework made up of a base 6 having legs I and supporting a hollow frame body 8. Body 8 is open at the bottom and base 6 at the top, as indicated at 9, to provide free space for the plunger operating mechanism described later. Machine screws H or the like secure base 6 and the frame body 8 together about their abutting edges.

.Frame body 8 has an upright extension or hot plate l2 to which the fixed half I3 of the die is removably secured in any suitable manner. The movable half I of the die is detachably aflixed to one end of a ram l6 mounted for' reciprocation in an opening I'I extending through a second upright It on the opposite end of the machine. A pinion l9 ismounted in standard I8 and meshes with gear teeth 2| on ram it, so that rotation of the pinion in one direction serves to open the die, and rotation in the opposite direction serves to close it. Hand wheel 22 forms the operating means for the pinion.

Toggle means are interposed between the opposite end of ram l6 and aportion 23 of the frame body 8 to lock the die in closed position, as shown in Fig. 1. The toggle means comprise a link 24 pivotally connected at 25 to the ram andalso pivotally connected at 26 to a second link 21. The latter is pivotally connected at 28 to the frame, this pivotal connection being adjustable by set screw means 29, so that the toggle locking mechanism will function properly when used with dies of different thicknesses.

An upright link 30 is pivotally connected at 26 to the toggle means for operating the same. The lower end of this link pivotally connects at 3! with a lock lever 32 pivotally mounted at 33 on a leg I of the machine. With the parts in the position of Fig. 1, if the operator depresses the left end 34 of lever 32, link 30 will break the toggle formed by links 24 and 2! upwardly, so that hand wheel 22 may be turned to quickly open the die. To close ,the die and lock it, hand wheel 22 is rotated in the opposite direction, and, as the die part l4 approaches closed position, the operator steps on the opposite end 35 of lever 32. This causes link 30 to straighten out the toggle and thus tightly lock die part it against stationary die part l3.

The closed die, as most clearly shown in Fig. 3, has a casting cavity 35, a restricted ingate passage 31 and a communicating, cylindrical pressure chamber 38 which opens at 39 on the bottom face of the die. Chamber 38 is located on the parting line of the die with a portion of the chamber formed in each half of the die. This chamber is adapted to receive the charge of molten metal for the die through its open bottom end 39, the metal then being forced through ingate 31 and compressed under high pressure in the die cavity 36 by the metal supplying, transferring and compressing means now to be described.

Frame body 8 has a horizontal portion 4| formed with a vertical, cylindrical portion 42 having a passage 43 extending therethrough. Snugly, but slidably, mounted in passage 43 is a cylindrical molten metal magazine or well 44 having a removable bushing or liner. 46. The well is rabbeted at 41 and the liner flanged at 48 to support the latter in place in the well, but permit its removal for renewal purposes. Liner 46 is arranged in exact alinement with cylindrical pressure chamber 38 in the closed die, and its interior diameter corresponds substantially to that of the pressure chamber.

Well 44 has a flange 49 substantially encircling its upper end. Surrounding the well between flange 49 and the upper end of cylindrical portion 42 of the machine frame, is a series of stacked, ring-like members 5|. These members serve to support the upper end of the well in close proximity to the bottom face of the closed die, as shown in Figs. 1 and 3. One of the ring-like members 5i is shown in perspective in Fig. 4. Some of these members preferably are made of different thicknesses for a purpose explained later.

In order to insure exact alinement between well liner 46 and pressure chamber 38, guide pins 52, 52 are mounted on the upper end of well 44 and project snugly in corresponding sockets 53, 53 in the bottom edge of stationary die part l3 (see Figs. 2 and 3).

A plunger 54 is mounted for reciprocation in the lower open end of metal well 44 and controls the metal-receiving capacity thereof. When this plunger is in its lowermost position, as shown in Fig. l, and the movable die part I4 is retracted, molten metal from any convenient source of supply is ladled by the operator into the well above the plunger until well space 55 (Fig. l) is substantially full. The die is then closed by ma nipulation of hand wheel 22, and certain power means, described later, set into operation to raise plunger 54. The plunger transfers the charge of molten metal 56 from the well into pressure chamber 38 (as shown in Fig. 3), and then continues its upward movement in the pressure chamber, with which it has a rather close fit, to

force the metal through ingate 31 and into the die cavity 36. Plunger 54 is then operated to lower it into the well, the die is opened and the casting removed. The machine is now ready for the next casting operation.

The means for operating metal plunger 54 comprise a power piston 51 having a piston rod 51 connected to metal plunger 54, the piston 51 operating in a cylinder 58 supported by arms 59, 59 depending from the frame of the machine. These arms are bolted or otherwise rigidly secured at 60, 60 to the frame body 6. Cylinder 58 is pivotally connected at 6|, 6| to the lower ends of arms 59, 59 so as topermit vertical swinging movement of the cylinder for a purpose mentioned later. Cylinder 58 has suitable ports 62, 63

.61, 68, and 69.

adapted for the connection of hose or pipe, whereby compressed air or other motive fluid may be admitted to and exhausted from each end of the cylinder to positively move piston 51 in the desired direction. A suitable valve (not shown) is located at a convenient place on the machine for manipulation by the operator to cause movement of power piston 51 as desired.

A longitudinally adjustable connection is provided between metal plunger 54 and piston rod 51', so that the lowermost position of the plunger, i. e., the position of Fig. l with piston 51 against the lower end of cylinder 58, may be changed at will. Thus, there are present, for a purpose explained later, means for varying the volume of the space 55 in the well above plunger 54 and, hence, the size of the charge of metal 56 which this space receives for transference to the die.

The adjustable connection referred to comprises a cylindrical coupling assembly, including a main coupling member 64 and a complementary, semicylindrical coupling member 65. Machine screws 66, 66 serve to secure these coupling members together, but when the screws are removed, member 65 may be separated from member 64 on lines When assembled, the coupling presents a chamber 16, an upper opening 1i through which plunger 54 freely extends and an annular groove 12 in which is located an annular flange 13 on the plunger. The upper end of piston rod 51 is threaded and extends into a threaded opening 14 in a base portion 15 formed on coupling member 64. A lock nut 16 for the coupling is also provided.

It will thus be seen that the coupling assembly may be rotated on piston rod 51' to raise or lower plunger 54 to any desired position in the metal.

charge of metal 56 were placed under pressure before plunger 54 entered pressure chamber 38, which pressure for instance would be created by resistance of the metal to free passage through ingate 31 and into the die cavity, molten metal under high pressure would escape from between the upper end of well 44 and the bottom of the closed die, unless a tight fit were provided between these parts. In order to eliminate this danger and obviate the necessity of a close fit between the top of the well and the multi-part die, particularly part I4 thereof which must be adapted for free opening and closing movement, provision is made for transferring the entire charge of metal 56 from the well to the closed die before the metal is placed under pressure.

This is accomplished by properly proportioning the volumetric capacities of pressure chamber 38 and well space 55 (Fig. 1) with reference to the size of the particular casting being made, i. e., the volume of metal necessary to fill die cavity 36 and extend sufficiently far down into pressure chamber 38 to permit plunger 54 to act thereon and force the metal into all parts of the cavity. This volume determines the size of the metal charge 56 which is to be placed in metal well 44.

area-see particular casting being known, and plunger 54 being in its lowermost'or charge-receiving position of Fig. 1--with the die open, the adjustable coupling between plunger 54 and piston rod 51' is rotated to, move plunger 54 up or down in well 44 until wellvolume 55 above the plunger is equal to the volume of metal required to make the casting. Molten metal is then ladled into the well until it is substantially full, and the die is closed. The power means described are then set into operation to cause plunger 54 to rise and move the metal charge 56 into pressure chamber 38. This transference of the metal charge into chamber 38 is eifected before the metal is placed under pressure by making the pressure chamber of a capacity suilicient to receive the entire charge of metal for the casting being produced, and by so shaping pressure chamber 38 as to permit free movement of the charge of metal therethrough until plunger 54 enters the pressure chamber, as shown in Fig. 3. Thus, by the time the metal charge 55 is placed under pressure, which does not occur until the metal seeks topass through the restricted ingate passage 31 and into the restricted parts of the die cavity, plunger 54 has passed beyond and sealed the joint between the die parts and the top of well 44 so as to preclude all possibility of metal under pressure escaping at this point.

1 In order to realize the advantages of the present improvements when a die for producing a smaller or a larger casting is substituted, it is necessary to maintain the above described relationship between the capacity and shape of pressure chamber 38 in the die and the capacity of well space 55, and the volume of metal necessary to make the casting. In other words, the capac.--

ity of well space 55 must be changed so that, when full, it will contain a metal charge of proper volume to meet the requirements of the casting being made. Likewise, the volumetric capacity of the pressure chamber 38 in different dies will be controlledby the size of the casting.

Ring-like members 5|, as-stated, serve to hold well 44 in close proximity to the bottom of the die. When the die is open and die part l3 re- ,moved, well 44 with its liner 46 may be lifted out from above for renewal, repair or other purposes. With well 44 removed, certain of the" ring-like members 5| may be interchanged for other similar members of different thicknesses, or certain of them may be added or removed, in order to vary the height at which these members support well 44 when the latter is in place Thus, provision is made to accommodate the height of the well to different sized dies, the bottom surfaces of which are disposed at diiierent levels when mounted in the machine.

Should it be desired to remove plunger 54 for renewal or other purposes, screws 66, are first removed and then coupling part 65. Piston rod 51' and cylinder 58 may then be swung towards the right on pivots 6|, 6| (Fig. l) to disconnect coupling member .64 from plunger 54, whereupon the plunger is pulled through the bottom of well 44; or, when coupling member 65 is removed and there is no die inthe machine, well 44 and its liner may be removed and plunger 54 tilted in opening 43 to disengage it from coupling member 64 and permit its withdrawal from the machine. v

Although the present improved pressurecasting apparatus has been specifically described with reference to its use with molten metal, it is apparent that it is equally as well adapted for plunger means for transferring metal the eflieient production of high quality castings from metal in any other suitable moldable condition, such, for instance, as the plastic or socalled pasty state.

While a practical embodiment of the invention now in use has been illustrated and described onto the exterior of the mold; a substantially upright, tubular metal well mounted on the support with its upper end alined with said pressure chamber, said well having a flange at its upper end and being vertically adjustable to locate it in close proximity to the bottom of the mold; a plurality of ring-like members, at least some of which are of different thicknesses, mounted on the well between said flange and the frame of the machine to maintain the well in position; and a plunger mounted in the lower end of the well for reciproeatory movement in the well and the pressure chamber to transfer metal from the well into said chamber and thence into the mold cavity.

2. The combination in pressure casting appasaid opening in the mold; a plurality of different sized removable elements interposed between the support and a portion of the well to maintain the well in close proximity to the mold; and from the well to the mold,

3.'In a'die casting machine, the combination of a frame; a bottom-gated, separable die comprising a fixed die half and a die half adapted for horizontal movement to open and close the die,the closed die having a casting cavity and a vertically disposed, vertically split, cylindrical pressure chamber, half of which is formed in each die half, communicating with the die cavity and opening onto the bottom of the die; a stationary, vertically disposed, tubular well mounted on the frame beneath the die with its upper open end in alinement with the pressure chamchamber permitting free passage of the metal whereby leakage of metal between the closed die and the well is prevented.

4. The combination in pressure casting apparatus of a bottom-gated, separable die comprisl ing a plurality of die parts adapted for substantially horizontal, relative movement between die open and die closed positions, the closed die having a casting cavity and a split pressure chamber formed by the die parts, said pressure chamber communicating with the die cavity and opening on o the bottom of the die; a tubular, upright well positioned beneath the closed die with its upper open endin alinement with the pressure chamber in the die but slightly spaced from the bottom of the die to permit freely said relative movement of the die parts; and a plunger in the well adapted for movement therethrough and into the pressure chamber -to transfer metal from the well into said chamber and thence into the die cavity, said pressure chamber permitting free passage of the metal whereby leakage of metal between the closed die and the well is prevented.

5. The combination of claim 4, wherein said well is adapted, when the plunger is lowered, to receive a metal charge of sufficient volume to fill the die cavity and extend into the pressure chamber, further characterized in that the pressure chamber in the closed die has a volume sufiicient to receive said entire metal charge and is shaped to permit free movement of the entire charge therethrough until the plunger enters the pressure chamber, whereby to prevent escape of metal under pressure from between the well and the closed die when the plunger forces the metal from the pressure chamber into the die cavity.

6. The combination in pressure casting appa ratus of a bottom-gated, separable die comprising a plurality of die parts adapted for substantially horizontal, relative movement between die open and die closed positions, the closed die having a casting cavity and a split pressure chamber formed by the die parts, said pressure chamber communicating with the die cavity and opening onto the bottom of the die; a tubular, upright well positioned beneath the closed die with its upper open end in alinement with the pressure chamber in the die but slightly spaced from the bottom of the die to permit freely said relative movement of the die parts; a plunger in the well adapted for movement therethrough and into the pressure chamber to transfer metal from the well into said chamber and thence into the die cavity; and means for limiting retraction of the plunger, the well being adapted, when the plunger is at its limit of retraction, to be filled with a charge of metal, which charge is of sufflcient volume to fill the die cavity and extend into the pressure chamber, and the pressure chamber having a volume greater than that of said entire metal charge and being so shaped as to permit free movement of the entire charge therethrough until the plunger enters the pressure chamber, whereby to prevent escape of metal under pressure from. between the well and the closed die when the plunger forces the metal from the pressure chamber into the die cavity.

7. The combination in pressure casting apparatus of a bottom-gated, separable die comprising a plurality of die parts adapted for substantially horizontal relative movement between die open and die closed positions, the closed die having a casting cavity and a split pressure chamber formed by the die parts, said pressure chamber communicating with the die cavity and opening onto the bottom of the die; a stationary, upright, tubular well located beneath the closed die with its upper open end in alinement with the pressure chamber in the die, said upper end of the well being flat and slightly spaced from the bottom of the die to permit freely said relative movement of the die parts; and a plunger in the well adapted for movement therethrough and into the pressure chamber to transfer metal from the well into said chamber and thence into the die cavity, said pressure chamber permitting free passage of the metal, whereby leakage of metal between the closed die and the well is prevented.

8. The combination in pressure casting apparatus of a split gate, separable die comprising a plurality of die parts adapted for relative horizontal movement towards and from each other during closing and opening of the die, the closed die having a casting cavity and a vertically, axially split pressure chamber formed by the die parts, said pressure chamber communicating with the die cavity and opening onto the bottom of the die; a vertical, tubular metal well positioned below said closed die and having its upper open end in alinement with the pressure chamber in the die; and a plunger in the lower part of the well adapted for movement therethrough and into the pressure chamber to transfer metal from the well into said chamber and thence into the die cavity, said well being adapted, when the plunger is retracted, to receive a metal charge of sufiicient volume to fill said die cavity and extend into the pressure chamber, and said pressure chamber having a volume suflicient to receive said entire metal charge and being so shaped as to permit free movement of the entire charge therethrough until the plunger enters the pressure chamber, whereby to prevent escape of metal under pressure from between the well and the closed die when the plunger forces the metal from the pressure chamber into the die cavity.

9. The combination in pressure casting apparatus of a bottom-gated, separable die comprising a plurality of die parts adapted for substantially horizontal, relative movement between die open and die closed positions, the closed die having a casting cavity and a split pressure chamber formed by the die parts, said pressure chamber communicating with the die cavity and opening onto the bottom of the die; a tubular, upright well positioned beneath the closed die with its upper open end in alinement with the pressure chamber in the die but slightly spaced from the bottom of a die part adapted for movement with reference to said well in opening and closing the die, whereby to permit freely said relative movement of the die parts; and a plunger in the well adapted for movement therethrough and into the pressure chamber to transfer metal from the well into said chamber and thence into the die cavity, said pressure chamber permitting free passage of the metal whereby leakage of metal between the closed die and the well is prevented.

10. The combination in pressure casting apparatus of a bottom-gated, separable die comprising a pluralitg of die parts adapted for substantially horizontal, relative movement between die open and die closed positions, the closed die having a casting cavity and a split pressure chamber formed by the die parts, said pressure chamber communicating with the die cavity and opening onto the bottom of the die; a tubular, upright well positioned beneath the closed die with its upper open end in alinement with the pressure chamber in the die but slightly spaced from the bottom of the die to permit freely said relative movement of the die parts; a plunger in the well adapted for movement therethrough and into the pressure chamber to transfer metal from the well into said chamber and-thence into the die cavity; means for limiting retraction of the plunger, the well being adapted, when the plunger is retracted, to receive a metal char e of sufllcient volume to fill the die cavity and extend into the pressure chamber, and the pressure chamber in the closed die having a volume sufficient to receive said entire metal charge and being so shaped as to permit free movement of the entire charge therethrough until the plunger QALOSALSQ enters the pressure chamber, whereby to prevent escape of metal under pressure from between the well and the closed die when the plunger forces the metal from the pressure chamber into the die cavity; and means for adjusting said plunger limiting means, so as to vary the limit of retraction of the plunger and consequently the depth and capacity of the upright metalreceiving well, whereby to accommcdate dies adaptedto produce diflerent sized castings.

"RAYMOND J. scmmrz. 

